Roughly 70 people gathered in Lame Deer Wednesday on what would’ve been Henny Scott’s fifteenth birthday.

Scott’s body was found late last month near her community on the Northern Cheyenne reservation in southeastern Montana. She is one of many indigenous women and girls who have gone missing across North America in recent years.

Robin Sterritt, a mechanical engineer who’s lived in Colstrip, Montana, for thirty years, points to the cloud of steam where the town’s famous smokestacks typically loom. It’s four degrees and the towers are hidden behind the heavy fog. “A day like today, everybody’s got the heat on,” he said.

Normally the smokestacks are hard to miss; they’re the tallest man-made structures in the state. On a clear day, you can see them thirty miles before you drive into Colstrip, a tidy town of 2300 in the southeast corner of Montana. Colstrip isn’t on the way to many places. It’s out here for only one reason: coal.